Improved propeller



UNITED STATES PATENT OFFICE.

IM PROVED PROPELLER.

Specification forming part of Letters Patent No. 42,870, dated May 14,1864.

To all whom it may concern:

Be it known that I, GRENVILLE PARKER, of the city and county of Vorcester, and Oommonwealth of Massachusetts, have invented certain new and useful improvements in the structure and arrangement of the propellingwheel and other appendages of steamboats, with a view to adapt them to the navigation of canals and other narrow or shallow waters; and I declare the following` to be a full, clear, and exact description of the same, reference being had to the annexed drawings, in which- Y Figures 1 and 2 represent my improved bucket; Fig. 3, a horizontal section of a hull, and Fig. 4 a side view of a boat with my improvements applied, one leg of the hull be ing 'removed to exhibit more fully thc improvements and their operation.

It has long been a desideratum to so construct and arrange with a hull apropellingwheel as to enable the boat to navigate canals and other narrow or shallow waters without exposing the wheel to collision with the banks, bottom, or other objects, and the banks and bottoms of canals to abrasion and disturbance from the action of the wheel; and various attempts have been made to accomplish the desirable object. One was by placing the ordinary paddle-wheel in a channel which extended the whole length of the boat. The destruction of the boats bearings thereby, with a difculty in steering, especially against currents and the large waves such a wheel set out at the stern of the boat, soon demonstrated the in adequacy of the plan. The same object has also been sought by placing a similar wheel in a channel which extended only a part of the boats length, from the midship or some point aft to the stern. But it was found that a wheel of this description would not get the requisite hold upon the water in that position unless its width and diameter were greater than the locks and bridges would admit, orv the buckets were dropped below the bottom of the boat, and consequently exposed to injury themselves from collision, and to catch tow-lines and disturb the bottoms of canals. Besides, such a wheel created too much agitation of the water to be allayed without the expenditure of considerable power. Much power was also lost by the water escaping over and eluding laterally the ordinary plane paddle and wedging between it and the side of the channel. Differentlyconstructed wheels have also been placed in Wells in the boats bottom, without any outlet for the escape of the water at the stern; and it was found in such cases that the reaction of the water nearly equaled the propulsive force of the wheel.

l have accomplished the desired result by constructing the propelling wheel A,A Fig. 4. When paddles are made of boiler-iron and fastened permanently to the arms, as shown at a a, same figure, I make the side arms of sufficient width to drop back of the paddle and increase the backing power of the wheel. The form of my paddle is the curved surface of half the frustum of a cone, (Fig. 1 b b b b,) or it may be one-half the frustrum of the wedge, with its outside surface thrown into a parabolic or other curve in place of its plane angular sides, (see Fig. 2, c 0 c 0,) and also, instead ofthe wedge proper, its lateral perpendicular lines may converge, as shown by the red lines in the same figure. The wedge form is` preferable when the paddle is to be fitted to side arms which stand at rightl angles with the shaft, as in wheel A. The parabolic curve is preferable, as that form takes the strongest hold on the water. The bases of the frustums are curved, so as to conform to the circumference of the wheel, Figs. 1 and 2. The height of the cone or wedge equals onehalf the wheels diameter. It may, if occasion requires, be less, in which case the paddles face will recede from the wheels radii. The increased height given to the paddles as the center arm is approached prevents the 'water from escaping over it when the paddle fills, as shown at d, Fig. 4. Its height for this purpose may be varied as occasion shall require. This wheel will tow a great load with comparatively little slip and loss of power in burying or lifting. The paddles entering the water feathering, as at j', Fig. 4, become lled at the point g,where the action is direct to propel the boat ahead. Their peculiar form gathers the water laterally and concentrates it as they enter, (see fand g, Fi g.'4,) and, as the water cannot escape over them when they fill,it opposes to them the greatest practicable resistance at the very point required. As soon as the side arms have passed the line of the wheels shaft, the paddle begins to fill, as at h, Fig. 4, and empties itself much faster than the ordinary-paddle, and with less commotion and loss of power, especially when towing. This wheel is peculiarly fitted to work in the channel of any ca-nal tug, as it will gel thl necessary foot-hold without dropping as low even as the bottom of the boat, and is not, therefore. exposed to collision itself', nor can it catch tow-lines nor disturb the bottoms of canals, even where the water is not more than three and a half or four feet deep and forty horsepower is applied. 'A hull of the limited demensions, which enable it to pass locks less than the ordinary size and low bridges, will admit a wheel on my plan which shall sustain a forty-horsepower engine and still possess all the necessary bearings. As the paddles leave the water with diminished agitation, a less expenditure of power is required for allaying the same.

As my paddles admit of no lateral escape of the water when filling, there is no power lost by the waters wedging between the ends ofthe buckets and sides of the channel, as is the case with the straight or plane bucket, which the water eludes; besides, as the water rushes up into the forward part of the cilannel in a somewhat broken state as the boat passes along, as seen at t', Fig. 4, the form of my buckets enables them to grasp and consolidate it, (see f and g, Fig. 4.) Vhen it would escape over and by the ordinay plane paddles the reverse action of my wheel will of course be less effective, yet with the aid of the side arms projecting backward, as before described, it is found to be sufficient for all ordinary purposes. But notwithstanding the peculiar structure ot' the propellingwheel made use of, there will, nevertheless, be waves, especially when a largeamount of power is applied of sufficient force and magnitude to injure considerably the banks of ordinary canals, and they must therefore be allayed, and with the least possible expenditure of power.

It was attempted by Mr. Taener, of England, (see Repertory of Patents, Plate 8, Vol. 10, Series 4,) to allay the commotion proceeding from a paddle-wheel placed in the channel of a boat by the use of aplatform placed permanently in the channal, aft the wheel, in a horizontal position, and on a level with the waters surface at the boats ordinary draft, and when the wheel was standing stili. This platform was as wide as the channel and eX- tended from the stern forward to the wheel, leaving room only for the wheel to revolve. There was an open space or chamber between thc platform and the top or covering of the channel, extending to the stern. His object was, by the near approach of the platform to the periphery of the wheel, to prevent its paddles (which were the ordinary plane ones) from raising the water as they emerged any more than possible; and, second, to dispose of such water as they should lift by throwing it upon the top of the platform and leaving it to find its way out over the platform asbest it could through the chamber to thc stern of the boat. The obvious and decisive objections to his plans are that the forward end of his platform, coming so near the wheel, must very greatly retard the action of the wheel and occasion great loss of power; and, second, that the water which is thrown vupon the platform will find its way out over its horizontal plane too gradually to keep the chamber clear, and, consequently, the chamber will become filled with water, which will react upon the wheel and at the same time greatly burden the boat. I allay the undulations gradually without any appreciable retardation of the boat or reaction of the water on the wheel by causing them to pass under the long and gradually-declining surface of my adjustable wave-queller YV, Fig. 4, which is suspended at its forward end by the roller or hinge k, and its after end by the screw J, which works in the nut o, which is fixed permanently in the deck. The forward end is placed a sufficient distance from the Wheel and above the Water to give the latter a free escape from the wheel by a roller working in the sides of the channel or hinges fastened' to the deckbeam. By means of the screw J the queller is shoved down until sufficient of its after portion is in contact with the water to 4produce the desired result; and whenever its tain the after portion of the boat; or it may be made of plank merely sawed or bent. into proper sha-pe and firmly bolted together. I place and arrange my wheel and queller in the channel or water-Way, substantially as shown in Fig. 4. 1n tug boats lprefer to commence the channel at or a little aft the midship section, but in such as are intended for carrying freight or passengers mainly it may be commenced farther aft, giving greater bearings to the boat, and extend it to the stern, giving in all cases free escape for the water from the wheel. As shown by Fig. 3, s s, I form the forward part or entrance to the channel or water-way by inclining the bottom of the boat upward in a gradual curve until it reaches the water-s surface in front of the wheel, as shown at p p, Fig. 4. More than one channel and wheel may be used, but one is deemed preferable, being less expensive and requiring less room.

Any form of hull may be adopted which shall best fit the navigation intended, care being taken to have the bottom flat, or as nearly so as practicable, in order to secure bearings and a light draft to the boat, which in ordinary canals in tug-boats should not eX- ceed two feet. The sides of the channel should be stron gly timbered andpla-nked like the other parts of the hull, and the wheel should be inclosed tight, so as not to throw water into the boat, with a door at the top giving access to the wheel. The boat can be easily steered by the use of two rudders, one on either side of the channel, or by one hung in the center thereof. The latter mode I deem the most convenient and most ei'ective.

Having thus described the nature and operation of my improved canal and river steamboat, I will state particularly what I claim therein as new and wish to secure by Letters Patent, that is to say- 1. Thepaddles or buckets to my wheel, hereinbefore described.

2. The position of my wheel, hereiubefore described, in an open channel, as before described, which sha-ll extend from the stern forward any part of the boats length.

GRENVILLE PARKER. 

